Determination of cichlid-specific biological reference points

Cichlid-specific biological reference points (BRI's) were calculated with combinations of two stock-recruit relationships within deterministic and stochastic frameworks. From a deterministic perspective, it was shown that spawner biomass-per-recruit should not be reduced to below 31% of pristine levels Such that the risk of recruitment failure is reduced while maintaining at least 75% of maximum yield. Stochastic simulations were more conservative and suggested that with the inclusion of recruitment variability and error in accurately calculating a reference point that spawner biomass-per-recruit should not be reduced to below 40-50%. It is, therefore, suggested that fishing mortality be maintained at no more than that required to reduce spawner biomass-per-recruit to 40% of pristine levels if the form of the spawner-recruit relationship is Unknown. It is further argued that a Beverton-Holt spawner-recruit relationship is possibly the most plausible given current knowledge on cichlid life histories. Spawner biomass-per-recruit Should, therefore, given process uncertainty not be allowed to fall below 45% of unfished levels. (C) 2003 Elsevier B.V. All rights reserved.